Glass grinding and polishing machine



IOct. 19, 1943.

GLASS P. MACA GRINDING AND POLISHING MACHINE Filed March 20, 1941 12 Sheets-Sheet 1 Oct. 19, 1943. P. MAcA GLASS GRINDING AND POLISHING MACHINE Filed March 20, 1941 12 Sheets-Sheet 2 jw/e'fzof: Paal ,/aca @if w ff/omega Oct. 19, 1943. P, MACA 2,332,329

A GLASS GRINDING AND POLISHING MACHINE Filed March 2o. 1941 12 sheets-sheet s HHIHU'W'- Il l' l 1' l [n 113 JW l 175 76 I 6 l Q7 l u 87 L' 86 o Q `l)- f/a g u 110 @D C@ l\ \\l\\\\ jfl jzwefzfor.' Paul aca @y d aafforzzeu ocr. 19, 1943,

P. MACA GLASS GRINDING AND POLISHING MACHINE 12 Sheets-Sheet 4 Filed March 20. 1941 Oct. 19, 1943, P. MAcA 2,332,329

GLASS GRINDING AND POLISHING MACHINE AFiled March 20, 1941 T I J 12 Sheets-Sheet 5 Nl PaaL/ca Oct. 19, 1943. P. MACA 2,332,329

GLAss GRINDING AND PoLIsHING MACHINE Filed Mai-ch 20, 1941 12 Sheets-Sheet 6 Exam-mf -hmullnigi Y ocr. 19, 1943. P. MMAA 2,332,329

GLASS GRINDING AND PULISHING MACHINE Filed March 20, 1941 IZSheetS-Sheet 7 Oct. 19, 1943.

Filed March 20. 1941 /WWA M P, MACA GLASS GRINDING AND PQLISHING MACHINE 12 Sheets-Sheet 8 [12 #n for. fha] ./yaca am MJlKorlzz/s P. MCA

GLASS GRINDING AND POLISHING MACHINE och 19, v1943.

Filed March 20, 1941 l2 Sheets-Sheet 9 r. r w Wm w w .ma m ,:Xfd @M 5. n u u M (wld f P 3 W hnvd a 8 M M 3., M J 0.

Oct. 19, 1943.' P. MAcA GLASS GRINDING AND POLISHING MACHINE Filed March 20, 1941 12 Sheets-Sheet 10 a Jltornw WNW@ i Paal/Ya 0MM a-l oct. 19, 1943. P. MMA 2,332,329

GLASS GRINDING AND POLISHING MACHINE Filed llarch 20. 1941 12 Sheets-Shut 11 f64 1 QJ Oct. 19, 1943.

12 sheets-sheet 12 Filed March 20. 1941 w r m a J /M EwwN nl if@ PM l, SN |12 y J L l lqil SNN QM. MNM@ vil nulinullvl Patented Oct. 19, 1943 GLASS GRINDING AND POLISHING MACHINE Paul Maca, Chicago, Ill.

Application March 20, 1941, Serial No. 384,295

9 Claims.

This invention relates to a glass grinding and shing machine.

More particularly, this invention relates to a glass grinding and polishing machine which is particularly adapted for grinding and polishing the peripheral edges or edge portions of glass or ceramic sheets.

Heretofore in the glass industry and in like ceramic arts, in order to grind or polish the peripheral edge of a sheet of glass or like ceramic material, it has been customary for the workman to hold the sheet against a rotating abrasive element or wheel and it will be appreciated that this manual method has a number of disadvantages in that it is not only slow and laborious but also has the additional disadvantage which resides in the fact that it is impossible in this way to provide a uniformly shaped peripheral edge or edge portion of a desired shape or configuration on a glass or like ceramic sheet.

It will also be appreciated that in the practice of prior art manual method of grinding, smoothing or polishing the peripheral edge or edge por- ;v--tions of glass or like ceramic sheets it was impossible to assure that all of the jagged or sharp surfaces or points thereon would beeliminated and the peripheral edge of the glass sheet made uniformly smooth during the grinding or polishing operation with the result that jagged or sharp points would frequently be found upon the peripheral edge or edge portion of glass sheets thus manually polished or buifed.

Another disadvantage in the use of the prior art practice of manually grinding glass or like ceramic sheets is that it was impossible by the use of this manual method to provide uniformly l,beveled edges on such glass or like ceramic sheets.

A further disadvantage in the use of the prior i art practice of manually grinding the peripheral edge or edge portion of glass or like ceramicv E sheets resided in the fact that it was difficult in the use of that method to provide a uniform selected or desired shape or configuration in the peripheral edge or edge portion of glass or like ceramic sheets, including a fiat or straight sided edge, a beveled edge, a rounded convex edge, and Larounded concave edge.

An additional disadvantage of the prior art l practice of grinding, polishing or smoothing glass and like ceramic sheets resided in the fact that it l was impossible particularly in the case of circular glass sheets to assure that the sheet would not be ,ground slightly out of its true or initial shape j digng the grinding or polishing operation.

effect and realize novel apparatus by means of which the peripheral edge or edge portions of a sheet of glass or like ceramic material may be expeditiously and mechanically ground or polished to provide a peripheral edge or edge portion of a desired shape or configuration thereo.

Another object of the invention is to provide a novel apparatus by means of which the peripheral edge of a circular glass or like ceramic sheet or disc may be expeditiously ground or polished to provide a uniformly shaped edge of a desired configuration thereon.

Another object of the invention is to provide a glass polishing and grinding apparatus which includes a novel device for holding a circular sheet of glass or like ceramic material in position during the operation of grinding or polishing its peripheral edge.

Another object of the invention is to provide a novel and efficient device for grinding or polishing the peripheral edge of a circular glass sheet or disc.

Another object of the present invention is to employ a continuously movable endless abrasive belt in the new glass grinding and polishing machine for grinding or polishing the peripheral edge of a circular or non-circular or angularly formed sheet of glass or like ceramic material and to provide a novel device, embodied in the new glass grinding and polishing machine, for controllingand varying the angle or path of travel at which the abrasive surface of the movable abrasive endless belt engages the peripheral edge of the glass or like ceramic sheet during the grinding or polishing operation.

Another object of the invention is toavary and control the angle or path of travel ativvhich the abrasive surface of the endless abrasive belt engages the peripheral edge of a glass or like ceramic sheet, during the grinding or polishing operation, in such a manner as either to grind the peripheral edge of a glass or like ceramic sheet or to impart a desired shape or configuration thereto such, for example, as a straight-sided or a beveled or a rounded edge thereon, depending upon the path of travel of the movable abrasive belt at the point where the abrasive surface thereof engages the peripheral edge or edge portion of the glass or like ceramic sheet during the grinding or polishing operation.

A further object of the invention is to provide, in one embodiment thereof, novel manipulative means for adjusting the turntable-supporting carriage and the turntable carried thereby rela- Accordinglm an object of this invention is to tive to or toward and away from the abrasive belt which is embodied in the new glass grinding and polishing machine.

Another object of the invention is to provide, in one form thereof, novel manipulative means for yieldingly urging the peripheral edge portion of a glass disc supported on a turntable which is embodied in said form of the invention, against the abrasive belt which is embodied in the said form of the new glass grinding and polishing -v machine; and to control by said novel manipulative means, the yielding contact or pressure of the peripheral edge portion of the glass disc against the abrasive belt so that said yielding contact or pressure may be relatively slight or less at rst, to enable the jagged surfaces or sharp points on the peripheral edge of the glass disc to be eliminated, without tearing or rupturing the abrasive belt, whereupon the yielding pressure or contact of the peripheral edge portion of the glass disc against the abrasive surface of the abrasive belt may be increased to complete the grinding or polishing operation.

A further object of the invention is to provide, in one form of the invention, a novel device for adjusting a circular glass sheet or disc into and out of contact with a moving abrasive endless belt which is embodied in the new glass grinding and polishing machine.

Another object of the invention is to provide a novel device, which is embodied in one form of the invention, for urging the peripheral edge portion of a circular glass sheet or disc into engagement with the movable abrasive endless belt which is embodied in the new glass grinding and polishing machine.

A further object of the invention is to provide novel devices, which are embodied in one form of the invention, for continuously rotating a substantially circular glass or like ceramic sheet or disc with its peripheral edge portion in engagement with the abrasive surface of a continuously moving abrasive endless belt which, at the same time, yieldingly urge the peripheral edge portion of said substantially circular glass or like ceramic sheet into engagement with the abrasive surface of the continuously moving abrasive endless belt.

An additional object of the invention is to construct and arrange one form of the new machine in such a manner that the supporting carriage, including the turntable, with a circular sheet of glass or like ceramic material disposed thereon, may be moved or adjusted laterally relative to the movable abrasive endless belt so as to utilize, at different times, all of the abrasive surface of the movable abrasive endless belt, that is, the entire width of the same.

A further object of the invention is to provide a novel device by means of which the abrasive surface of the abrasive endless belt which is ernbodied in the new glass grinding and polishing machine may be held in nat contact with the peripheral edge of a glass or like ceramic sheet during the grinding or polishing operation so as to form, as may be desired, either a straightsided peripheral edge or a beveled edge on the peripheral edge of the glass sheets.

Other and further objects of the present invention will be apparent from the following description and claims and are illustrated in the accompanying drawings which, by way of illustration, show preferred embodiments and the principles thereof and what I now consider to be the best modes in which I have contemplated applying those principles. Other embodiments of the invention embodying the same or equivalent principles may be used and structural changes may be made as desired by those skilled in the art without departing from the present invention and the purview of the appended claims.

In the drawings,

Fig. l is a side elevational view of a preferred form of the new glass grinding and polishing apparatus which is particularly constructed and arranged for grinding or polishing the peripheral edge of a substantially circular sheet or disc of glass or like ceramic material;

Fig. 2 is a top plan view of the apparatus which is illustrated in Fig. 1;

Fig. 3 is a front end elevational view of the same;

Fig. 4 is a side elevational view of that form of the novel glass grinding and polishing apparatus which is shown in Figs. 1 to 3, inclusive;

Fig. 5 is an enlarged vertical sectional view on line 5-5 in Fig. 2, showing the construction of the turntable and sheet-holding device and associated parts;

Fig. 6 is an enlarged vertical sectional view on line 6-6 in Fig. 5, showing the construction of the turntable-supporting carriage and the guiding means therefor;

Fig. 7 is a view on the line 1-1 in Fig. 5, partly in section and partly in top plan;

Fig. 8 is a fragmentary sectional view on the line 8 8 in Fig. 9, partly in section and partly in plan, showing a part of the manipulative mechanism for latching and operating the turntablesupporting carriage;

Fig. 9 is a fragmentary side elevational view of the structure which is shown in Fig. 8;

Fig. l0 is a sectional View on line lll-I0 in Fig. 9, and showing, among other things, the guiding structure for the turntable-supporting carriage;

Fig. l1 is an enlarged sectional view on line lI-H in Fig. l2 showing one form of the novel device embodied in the new glass grinding and polishing machine for controlling the path of travel of the abrasive endless belt at the point where, or the angle at which, the abrasive belt engages the peripheral edge of a circular glass or like ceramic sheet;

Fig. 12 is a fragmentary side elevational view of the device which is shown in Fig. 11;

Fig. 13 is a fragmentary detail top plan view on line I3|3 in Fig. 12;

Fig. 14 is an enlarged detail elevational view showing a novel belt-tensioning device which is embodied in the form of the new glass grinding and polishing machine which is shown in Figs. 1 to 13, inclusive, for tensioning the movable abrasive endless belt;

Fig. 15 is a sectional top plan view on line |5-l5 in Fig. 14, of the belt-tensioning device which is shown in Fig. 14;

Fig. 16 is a sectional view, on line lli- 16 in Fig. 17, showing a device which is embodied in the new glass grinding and polishing machine for holding the movable abrasive endless belt in ilat Contactl with the peripheral edge of a sheet of glass or like ceramic material and positioned to provide a straight-sided edge on the peripheral edge of said sheet 0f glass or like ceramic material;

Fig. 17 is a side elevational view of the device which is shown in Fig. 16;

Fig. 18 is an elevational view, on line l8-l8 in Fig. 20, and Fig. 20 is a side elevational View of the abrasive belt-guiding device which is illustrated in Figs. 16 and 17, and associated beltguiding rollers, adjusted or positioned in such a manner as to cause the abrasive belt to form a beveled edge on the peripheral edge of a sheet of glass or like ceramic material disposed in contact therewith; and

Fig. 19 is a view similar to Figs. 18 and 20 but showing the abrasive belt-guiding device which is illustrated in Figs. 18 and 20 positioned to provide a beveled edge on a glass sheet but which beveled edge has a somewhatJ different and sharper angle than the beveled edge which is formed on the glass sheet when the parts are positioned as shown in Fig. 20.

A typical embodiment of the invention is illustrated in Figs. 1 to 20, inclusive, and this form of the invention is particularly adapted and constructed and arranged for polishing and grinding the peripheral `edges of substantially circular sheets of glass or like ceramic material such as the glass disc which is indicated at 35. This form of the invention comprises, in general, two units, namely, a device for holding and rotating a substantially circular sheet or disc 35 of glass or like ceramic material and a device for operating a movable abrasive member, such as the abrasive endless belt 35, in contact with the peripheral edge of the substantially circular glass sheet or disc 35.

In order that the general mode of operation of the invention may better be understood, it may be stated, before proceeding with a detailed description of the form of the new glass grinding and polishing machine which is illustrated in Figs. 1 to 20, inclusive, that in the use of the same the substantially circular glass sheet or disc 35 is mounted upon a turntable 31 which includes a rubber ring 38 whereon the circular glass sheet or disc 35 is held by means of Vacuum exerted through a line 39, the turntable being rotated by a motor-driven mechanism which will be described hereinafter.

The moving abrasive endless belt 35 is guidedv over suitable guide rollers, such as 40 and 4|, which are mounted in a supporting frame 42, and the abrasive belt 36 is moved in a generally vertical direction by means of a motor-driven operating unit which is indicated at 43 in the drawings.

In the use of that form of the new glass grinding and polishing mechanism which is illustrated in Figs. l to 20, inclusive, the substantially circular glass sheet or disc 35 is arranged on the turntable 31--38 and suction or vacuum is applied thereto, through the line 39, so as to hold the circular glass sheet or disc 35 on the turntable 31 which is urged, by a weight 85 and associated parts, toward the abrasive belt 36, so as to yieldingly urge the peripheral edge of the circular glass sheet or disc 35 on the turntable 31 into contact with the moving abrasive endless belt 36 and thus grind or polish the peripheral edge of the glass sheet or disc 35, as will be eX- plained more in detail hereinafter.

Having thus indicated briefly the general mode of operation of the invention, a detailed description of the construction of that form of the same which is illustrated in Figs. 1 to 20, inclusive, will now be given.

Turntable and glass disc-holding device The turntable and glass disc-holding or suction device which are embodied in the form of the new glass grinding and polishing machine which is shown in Figs 1 to 20, inclusive, is best illustrated in Figs. 5, 6 and 7, and comprises a rotary turntable 31 having an upright side wall 44 and top wall 45. An internally grooved or channel-shaped rubber ring 38 embraces the peripheral edge portion of the top wall of the turntable 31 and the circular glass sheet or disc 35 rests on this rubber ring and is thereby spaced slightly above the top wall 45 of the turntable 31, thus providing a space or area 46 between the top wall 45 of the turntable and the bottom of the glass disc 35 which is arranged thereon.

Communicating with the area 46 is a suction or vacuum line 39 and this line 39 is arranged within a tubular shaft 41 on which the turntable 31 is mounted, this shaft 41 being journaled in bearings 48 which are, in turn, carried by a supporting structure 49 which is mounted on the supporting frame 50 of the machine.

The suction or Vacuum line 39 communicates, by way of a line 5|, with line 52 which extends between the vacuum tank 53 and an air exhaust pump 54 which is driven by a motor 55 which is mounted on turntable-supporting carriage 511, the motor 55 being operatively connected to the pump 54 by means of a suitable power-transmitting mechanism such as the belt 56 and pulley 5l.

A manually operable three-way valve 5B is arranged in the line 5| and a line 10 extends from the vacuum tank 53 to the operating motor 55 for the exhaust pump 54. An automatic control device 1| is arranged in this line 10 so as to control the speed of the motor 55 m accordance with the degree of vacuum or air pressure in the vacuum tank 53.

Arranged in the line 10, adjacent the vacuum tank 53, is a pressure responsive device 10A (Fig. 5) which may be a pressure-responsive switch for controlling operation of the motor 55 for the vacuum pump 54 so as to maintain a predetermined pressure in the vacuum tank 53.

The operating or rotating shaft 41 for the turntable 31 is driven through a clutch 59 and carries a gear 60 which meshes with a gear 5| which forms a part of a speed-reducing gear mechanism '62. This speed-reducing gear mechanism 62 is operated by means of a suitable power transmission device which is shown as comprising a shaft 63, pulley 64, belt 65, pulley 66 and motor 61, all of which parts are mounted on the turntablesupporting carriage 50, the belt and the pulley 54 being preferably of the V-shaped type and the pulley B6 being preferably a so-called Reeves or other similar type of pulley.

Associated with one element 12 of the clutch 59 is a yoke 13 which carries a manually operable handle or hand lever 14 for effecting engagement and disengagement of the clutch 59.

The turntable-operating motor 51 and the pulley 66 which is mounted on the shaft 68 of the motor 61 are adjustably mounted on the supporting frame 50, as shown in Fig. 7, and may be manually adjusted by means of a screw 63, which is provided with a handle '69A (Fig. 5), so as to vary the friction between the belt 65 and the pulleys 64 and 66 and thus vary the speed of the operating mechanism for the turntable 31 and the speed of rotation of the latter and the circular glass sheet or disc 35 carried thereby.

Turntable-supporting carriage and track structure The turntable-supporting carriage 50 includes oppositely disposed guide rollers 15 arranged at the sides thereof (Fig. 6). These guide rollers 15 ride on trackways 16 which are arranged upon the top of an undercarriage 11 and at opposite sides thereof.

Mounted upon an upward extension 18 of the undercarriage 11 is a pulley 19 and working over this, pulley is a exible element in the form of a chain 80. This chain 80 is adjustably attached, between its ends, as at 8|, to an upward extension or arm 82 of the turntable-supporting carriage 50, one end portion of this flexible element or chain 80 being adjustably attached, as at 83, tovan upward extension 84 of the undercarriage 11. A slide rod 86 is attached to a depending end portion of the exible element or chain 80, said slide rod 86 being slidably guided, as at 81, in the undercarriage 11, and a series or group of Scale weights 83 are mounted on the slide rod 86. The weights 83 serve to yieldingly urge the turntable-supporting carriage 50 and the turntable 31 carried thereby from left to right, as seen in Fig. 4, that is, toward the movable abrasive endless belt 36, so as to yieldingly urge the peripheral edge portion of the circular glass sheet or disc 35, which is mounted on the turntable 31, into contact with the abrasive surface of the abrasive belt 36, and the number of the scale weights 85 may be varied so as to vary the pressure of the peripheral edge portion of the glass sheet or disc 35 against the abrasive belt 36, the turntable carriage 50 being guided by movement of the guide rollers 15 over the trackways 16.

A hand lever 88 is pivotally mounted at its lower end, as at 89, upon a follower 90 and pivotally connected to this hand lever 88 between its ends as at 9|, is a latch lever or dog 92 which has a notched portion 93, as best shown in Figs 1 and 9. This latch lever or dog 92 has an upwardly extending arm 94 which is provided with a handle 95. The follower 90 includes a pair of threaded guide members 9S and threaded through these guide members is an adjusting screw 91 which is rotatably mounted at its ends, as at 98 and 99, on the undercarriage. A handle or hand wheel is provided at the outer end of the screw 91 to facilitate operation thereof.

The notched portion 93 of the latch dog or lever 92 is adapted for latching engagement with a latch keeper |0| which is provided on the follower 90.

The follower 90 is provided with upwardly extending arms |02 which are slidably guided between the trackways 96 and beveled upper end portions |03 which are provided on the undercarriage 11, as shown in Fig. 10.

Slidably mounted on the follower 90, (Figs. 8 and 9), as by means of a pin and slot connection |04A and HMB, respectively, is an adjustable stop 04 and the lever 88 is adapted to engage against one end portion |040 of this stop, under conditions which will be described presently. The slidable stop |04 also has a right angularly extending arm 184D which is provided with a resilient bumper IME and an adjusting screw |01, which is mounted in an arm |01A of the follower 90, bears at its inner end against the arm |04D of the adjustable stop |04 so as to vary the position of the latter to the hand lever 88.

The hand lever 88 is connected between its ends to the turntable-supporting carriage 50 by means of a pin and slot connection IBS-|06, as best shown in Figs. 9 and 1D, and a spring |09 on the bolt normally urges the hand lever 88 against the frame of the turntable-supporting carriage 50.

In order to effect an approximate adjustment between the turntable-supporting carriage 53, the turntable 31 and the glass sheet or disc 35 carried thereby relative to the abrasive belt 36, the hand lever 88 is retracted (left to right, Fig. l) and the notched portion 93 of the latch dog 92 is engaged with the latch keeper |0| provided on the follower 90. The screw 91 is then manipulated, by means of the hand wheel 0| thereon, so as to adjust the turntable-supporting carriage 50 relative to the undercarriage 11 and thus eiect an approximate adjustment of the turntable-supporting carriage 50, the turntable 31, and the glass sheet or disc 35 carried thereby relative to the movable abrasive belt 36. The latch dog 92 is then released from latching engagement, at 93-|0|, with the follower 90, whereupon the weights urge the turntable-supporting carriage 50, the turntable 31 and the glass disc 35 carried thereby toward the abrasive belt 36 so as to urge the peripheral edge portion of the glass sheet or disc 35 into engagement with the movable abrasive belt 36.

It will be noted that when the turntable-supporting carriage 50 is adjusted relative to the undercarriage 11, in the manner described above, the follower is guided by its upwardly extending arms |02, which are disposed between the trackways 16 and the beveled upper edges |03 of the undercarriage 11, and that when the latch dog 92 is released from latching engagement with the latch keeper |0l, the hand lever 88 may be moved into engagement with the end portion |04C of the stop |04 (Figs. 8, 9 and 10) so as to eiect such an adjustment between the turntablesupporting carriage 50, the turntable 31 and the glass sheet or disc 35 carried by the turntable as will enable the relatively rough or jagged edges on the peripheral edge of the glass disc 35 to be polished off by contact with the abrasive surface of the abrasive belt 36.

The hand lever 88 may be moved laterally against the action of the springs |68 and |09 (Fig. 10) which are arranged on the bolts 89 and |05, so as to clear the end portion |040 of the stop |04 whereupon the hand lever 88 may be moved into engagement with the resilient element or bumper |04E which is carried by the arm |04D of the stop plate |04, the screw |01 being adjusted to vary the position of the stop plate |04 on the follower 90 and consequently the position of the turntable-supporting carriage 50 and the turntable 31 carried thereby relative to the undercarriage 11 and the abrasive belt 36.

The under-carriage 11, the turntable-supporting carriage 59, the turntable 31, and the circular glass sheet or disc 35 carried thereby, may also be adjusted laterally relative to the movable endless abrasive belt 36 on rollers |0 which are movable on trackways which are mounted upon the supporting surface or bed |2 of the machine.

As best shown in Figs. 1 and 6, a hand lever I3 is pivotally connected between its ends, as at |4, to the undercarriage 11 and this lever ||3 is also pivotally connected at its lower end, as at H5, to an upward extension ||6 of one of the trackways In order to eiect lateral adjustment of the turntable-supporting carriage 50, the turntable 31, and the glass sheet or disc 35 carried thereby, relative to the abrasive belt 36, the hand lever |3 may be manipulated and pivoted at |4 so as to move the undercarriage 11 laterally upon its supporting rollers |0 and along the trackways l, this movement being eiected by reason of the pivotal interconnection ||4 between the hand lever H3 and the pivotal interconnection ||5 between the hand lever ||3 and the stationary upward extension I6 of the guide rail It will thus be seen that by adjusting the turntable 31, its supporting carriage 50, and the undercarriage 11, laterally it is possible to utilize or use up, at different times, the entire eective abrasive surface of the abrasive belt 36.

Abrasive belt supporting and operating mechanism As shown in the drawings, the abrasive endless belt 36 works over guide rollers 40 and 4| which are mounted upon an upright supporting frame 42 and in the form of the invention which is illustrated in Figs. 1 to 20, inclusive, the supporting frame 42 for the abrasive belt 36 is shown as being stationarily mounted adjacent the turntable 31, the turntable-supporting carriage 50, and the undercarriage 11. The abrasive belt 36 may be operated in any suitable manner as, for example, by means of a suitable power transmission unit 43 which is mounted on the supporting frame 42.

The rear lap and the upper and lower portions of the front lap of the abrasive belt are enclosed within a housing ||1 which is open at its front side so as to expose the central portion of the front lap of the abrasive belt. The housing ||1 includes a sheet of flexible material ||8, such as rubber or the like, which extends around the rear and the sides of the rear lap of the abrasive belt 36 so as to prevent tearing of or damage to the abrasive belt 36 when the path of travel of the front lap thereof is varied and adjusted, as will be explained more fully hereinafter. A drain ||1A is provided at the bottom of the housing |1 (Fig. 3).

In order to prevent overheating of the abrasive belt 36 during the polishing and grinding operations, a hose ||9 is mounted on the supporting frame 42 and is adapted to be connected to any suitable source of water. This hose |9 is connected, at its lower end, to a nozzle which is mounted on the supporting frame 42, facing the abrasive surface of the front lap of the abrasive belt 36 and this nozzle |20 is controlled by a suitable hand valve |2| for the purpose of directing a stream of water from the supply hose H9 against the abrasive surface of the front lap of the abrasive belt 36 which engages the peripheral edge of the circular glass sheet or disc 35.

Abrasive belt tensioning device shown in Figs. 14 and 15 The present invention includes the provision of a novel device for tensioning the abrasive belt 36, and this belt-tensioning device is shown in detail in Figs. 14 and 15 wherein it is generally indicated at |22.

The belt-tensioning device |22 is mounted on a supporting bracket |23 which is, in turn, mounted on the supporting frame 42 for the abrasive belt 36, adjacent the upper end of the supporting frame 42. The belt tensioning device |22 includes a rotatable shaft |24 and the upper guide roller 40 for the abrasive belt 36 is mounted on this shaft |24. The shaft |24 carries a block |25 which is eccentrically mounted thereon, as shown in Figs. 14 and 15.

The eccentric block |25, which is mounted on the shaft |24, works in a housing |26 which is formed as a part of the bracket |23 and the eccentric block |25 is provided with an operating handle |21.

A slot |28 is formed in the housing |26 and projecting through this slot, and fastened in the eccentric block |25, is a bolt |29, on which a friction block |30 is mounted. This friction block |30 is urged into engagement with the outer surface of the housing |26 by means of a spring |3| which is mounted on the bolt |29.

In the use of the new glass grinding and polishing machine, the abrasive belt 36 may be tensioned by manipulating the handle |21, the eccentric element |25, the shaft |24, and the guide roller 40 on the shaft |24, so as to vary the tension of the upper guide roller 40 upon the abrasive belt 36, and the parts may be held in any desired adjusted position by the friction of the spring-urged block |30 against the outer surface of the housing |26.

The belt tensioning device |22, which is shown in Figs. 14 and 15, also includes means for adjusting the upper guide roller 40 (for the abrasive belt 36) laterally. This adjusting means takes the form of an adjusting screw 32, which is attached at its inner end to the supporting bracket |23, as at |33. This screw |32 is also mounted in an arm |34 of the supporting frame 42, and a handle or hand wheel |35 is provided on the screw |32 for manipulating the same.

Abrasive belt guiding and controlling device shown in Figs. 11 to 13, inclusive The new glass polishing and grinding machine includes novel means for varying and controlling the angle at which the abrasive surface of the abrasive belt 36 engages the peripheral edge portion of a circular glass sheet or disc 35 supported upon the turntable 31 and for varying and controlling the path of travel of the abrasive belt 36 at the point where its abrasive surface engages the peripheral edge portion of the glass disc 35 so as to control and vary the eect and the angle or curvature imparted to the peripheral edge of the circular glass sheet or disc 35 by the abrasive belt 36.

One embodiment of the novel means for controlling and varying the angle at which the abrasive belt 36 engages the peripheral edge portion of the glass sheet or disc 35, carried by the turntable 31, is shown in detail in Figs. 11 to 13, inclusive, wherein it is generally indicated at |36. This device |36 comprises a supporting bracket |31 which is removably mounted on the upright supporting frame 42 for the abrasive belt 36, by means of fastening elements such as bolts |38, and slidably mounted in a suitable bearing surface |39, which is provided in the bracket |31, is a supporting arm or rod |40. This rod may be adjusted in the bearing surface |39 and may be held in any desired adjusted position by means of a set screw |4| which is mounted in the bracket 31 and engages in a groove |40A which is formed in the supporting rod |40 to prevent the latter from turning or rotating.

The supporting rod |40 has a righ't-angularly and inwardly extending arm |42 which extends into the belt housing ||1 between the front and rear laps of the abrasive belt 36, as best shown in Fig. 11. Mounted upon the inwardly extending arm |42 of the supporting rod |40 is a supporting arm |43 which is adjustable about and relative to the arm |42 and may be held in any desired adjusted position thereon by means of a set screw |44 which is mounted in the collar |43 and which bears, at its inner end, against the arm |42 of the supporting rod |40.

A pair of roller hangers |45 and |46 are pivotally mounted on the supporting arm |43, one adjacent each end portion thereof. The roller hanger |45 carries a guide roller |41 and the hanger |46 carries a similar guide roller |48, these guide rollers |41 and |48 being rotatably mounted on stub shafts |50 and |5| which are carried by the hangers 45 and |46, respectively, (Fig. 12).

The hangers |45 and |46 and the belt guiding rollers |41 and |48 which are carried thereby are on th'e supporting arm |43, adjustable about their supporting pivots |52 and |53, respectively, so as to dispose the belt-guiding rollers |41 and |48 in various positions relative to each other and relative to the front lap of the abrasive belt 26, as will be described more in detail presently, and the guide roller hangers |45 and |46, and the guide rollers |41 and |48, respectively, which are carried thereby may be held in any desired adjusted position by means of clamping devices J, one of which is illustrated in Fig. 13.

Each of the clamping devices J comprises a serrated edge |54, one of which is formed on each of the hangers 45 and |46, and a complementary serrated edge |55 which is formed on the supporting arm |43, and which is engageable with the serrated edges |54 which are formed on the hangers |45 and |46. Each of the clamping devices J also include a thumb nut, such as |56, one of which is mounted on the threaded outer end portion of each of the pivots or bolts |52 and |53 on which the roller-supporting hangers |45 and |46, respectively, are mounted.

A typical use of the belt adjusting device which is shown in Figs. 11, 12 and 13 is illustrated in Fig. 12 wherein it will be seen that when it is desired to grind or polish the peripheral edge of a circular glass or like ceramic sheet or disc 35 carried by the turntable 31, the belt-guiding rollers |41 and |48 are arranged on opposite sides of, that is to say, above and below the glass disc 35 and the peripheral edge of the glass disc 35 is caused to bear against the abrasive surface of the abrasive belt 36 at a point approximately midway between the guide rollers |41 and |48 so as to form a loop in the movable abrasive endless belt 36. Hence it will be seen that as the movable abrasive endless belt 36 travels in a generally vertical direction across th'e peripheral edge of the glass disc 35, the loop portion |51 thereof will grind or polish the peripheral edge of the glass disc 35 and eliminate jagged or rough edges thereon and will form a rounded polished surface on the peripheral edge of the glass disc 35.

It will also be noted, by reference particularly to Fig. 12, that the position of the roller hangers |45 and |46, and of the rollers |41 and |48 which are carried thereby, and the path of travel of the front lap of the abrasive belt 36, may be controlled and varied so as to control the angular conguration or curvature imparted to the peripheral edge of the glass disc 35 by the abrasive belt 36.

Thus, it will be noted that with the parts disposed in the position in which they are shown in full lines in Fig. l2, the abrasive belt 36 will follow the path A, which is indicated in full lines in Fig. 12, whereas by moving the hangers |45 and |46, and the rollers |41 and |48 which are carried thereby into the positions in which these parts are shown in dotted lines in Fig. 12, the front lap of abrasive belt 36 will follow the path of travel in which it is shown in dotted lines, or in position B, Fig. 12, and in which position it will impart a different angular configuration or curvature to the peripheral edge of the glass disc 35 than is imparted thereto when the front lap of the abrasive belt 36 follows the path of travel in which it is shown in full lines or in position A in Fig. 12.

It will be seen, therefore, that by adjusting the hangers 45 and |46, and the rollers |41 and |46 which are carried thereby, it is possible to control and vary the path of travel of the front lap of the abrasive belt and, consequently` the curvature or conguration imparted to the peripheral edge of the glass or like ceramic disc 35, which is mounted on the turntable 31.

Modified form of abrasive belt guiding and controlling device shown in Figs. 16 to 20, inc.

A modified form of guiding and controlling device for the abrasive belt 36 is shown in Figs. 16 to 20, inclusive, and this form of the new abrasive belt guiding and controlling device is particularly adapted for use where it is desired to form either a straight-sided edge or a beveled edge upon the peripheral edge of a substantially circular glass sheet or disc 35 carried by the turntable 31.

'I'he form of the new abrasive belt guiding and controlling device which is shown in Figs. 16 to 20, inclusive, embodies a horizontally extending supporting bracket |58 which is adapted to be attached to the supporting frame 42.

The supporting bracket |58 may be attached to the supporting frame 42 in any suitable manner, as by means of bolts |59, which are projected through slots |60 which are formed in vertically extending arms |6| of the supporting bracket |56. Hence it will be seen that the supporting bracket |58 and the parts carried thereby are vertically adjustable on the supportingframe 42 by reason of the adjustable connection which is aorded by the bolts |59 and slots |60.

A channel-shaped groove |62 is formed in the supporting bracket 58 and a supporting arm |63 is slidably mounted in the groove |62. The supporting arm |63 is provided with a laterally extending internally threaded portion |64, and threaded into this portion |64 is an adjusting screw |65 which is provided with a handle in the form of a hand wheel |66. This adjusting screw |65vis also journaled in an opening which is formed in a laterally extending arm |13 of the bracket |58.

A supporting rod |61 is mounted on the outer end portion of the arm |63, and this rod |61 has a reduced end portion which is secured to the arm |63 by means of a nut |68which is threaded thereon.

A collar |69 is slidably and rotatably mounted on the supporting rod |61, and this collar |69 may be held in any desired adjusted position upon the supporting rod |61 by means of a set screw |10 which is mounted in a threaded opening which is provided in the collar |63, the inner end portion of the set screw |10 bearing against the supporting rod |61.

A shoe |1| is preferably formed as an integral extension of the collar |69 and this shoe |1| is provided with a resilient facing |12, which may be made of any suitable material such, for example, as leather, rubber or the like, and the .-1-7, that if and when it ls desired to provide a straight-sided peripheral edge upon the circular glass sheet or disc 35, this may be accomplished by adjusting the shoe |1|'-|12 so that the same extends in a substantially vertical plane with the face |12 thereof bearing against the inner or nonabrasive surface of the outer lap of the abrasive belt 36, causing the front lap of the abrasive belt 36 to run in a substantially vertical plane at the point where it engages the peripheral edge of the circular glass sheet or disc 35, and hence the engagement of the abrasive belt 36 with the circular glass sheet or disc 35 will form a straightsided peripheral edge upon the glass sheet or disc 35 which is carried by the turntable 31.

It will also be noted, by reference to Figs. 16 and 17, that the shoe |1|-|12 may be adjusted into any desired position upon the supporting rod |61, and may be secured therein by means of the set screw |10.

It will also be seen, by reference to Fig. 17, that a limited vertical adjustment of the shoe |1 12 may be effected by adjusting the bracket |58 and its arms |6| upon the bolts |59 which project through the slots |60, and that the shoe ITI-|12 may be adjusted toward and away from y the inner or non-abrasive surface of the front or outer lap of the abrasive belt 36 by means of the manually operable adjusting screw |65, and its handle |66, which, `when rotated, caused the supporting arm |63 to slide in the channel-shaped groove |62 which is formed in the supporting bracket |58.

An adaptation of the modified form of the new abrasive belt guiding and controlling device, which is shown in Figs. 16 and 17, is illustrated in Figs. 18, 19 and 20, which illustrates the use of the parts which are shown in Figs. 16 and 17 in combination with the parts which are shown in Figs. 11 to 13, inclusive Since certain of the parts which are illustrated in Figs. 18 to 20, inclusive, are identical in construction with corresponding parts which are shown in Figs. 11 t0 13, inclusive, these parts have been given the same reference numerals followed by the letter A, and those parts which are shown in Figs. 18 to 20 which are identical in construction with corresponding parts which are shown in Figs. 16 and 17 have been given the same reference numerals.

It will be noted by reference to Fig. 19 that the path of travel of the front or outer lap of the movable abrasive belt 36 is such, as is indicated at C, that it will form a beveled edge upon the glass sheet or disc 35 which is mounted on the turntable 31.

It will also be noted by reference to Fig. 19,

that the path of travel of the front or outerA lap of the abrasive belt 36, at the point where it engages the peripheral edge of the glass sheet or disc 35, and the resulting angle of the beveled edge formed on the latter, may be controlled by adjusting the upper guide roller hanger |45A, and the upper guide roller |41A which is mounted thereon, into the position in which these parts are shown in Fig. 19, and by adjusting the lower guide roller hanger HBA, and the belt guiding roller |48A, which is carried thereby, in the position in which these parts are shown in Fig. 19, and by adjusting the shoe I1 |-|12 into the position in which it is shown in Fig. 19.

When the parts are arranged as in Fig. 19 the first lap of the abrasive belt 36 travels between the guide rollers |41A and |48A and across the face of the shoe |1|-|12 at an acute angle with respect to the plane of the upper surface of the glass disc 35, which is mounted on the turntable 31, thereby forming a beveled peripheral edge, having a desired bevel or angle, on the glass disc 35.

The parts which are illustrated in Figs. 18 and 19 are shown in Fig. 20 also adjusted into a position to form a beveled peripheral edge on the Y glass disc 35 but at a somewhat different angle than the angle formed by the abrasive belt 36 when the parts are positioned as in Fig. 19.

Thus it will be seen that when the parts are disposed as in Fig. 20, the outer or front lap of the abrasive belt 36 will travel in a path which is indicated D in Fig. 20, and will travel between the upper and lower guide rollers |41A and |48A, respectively, and across the face |12 of the shoe |1| at such an angle as to form a beveled peripheral edge.

The guide roller 48A (Figs. 18, 19 and 20) is preferably provided with a hardened metallic face to resist the abrasive action of the abrasive surface of the front lap of the abrasive belt 36 which bears thereagainst.

General Operation of the Form o the Invention Which Is Illustrated in Figs. 1 to 20, Incl.

In the use of that form of the new glass polishing and grinding machine which is illustrated in Figs. 1 to 20, inclusive, the abrasive belt 36 may be properly tensioned for operation by manipulating the operating handle |21 of the belttensioning device |22, which is shown in Figs. 14 and 15.

In the event that it is desired to form a rounded peripheral edge on the circular glass sheet or disc 35, which is carried by the turntable, the beltguiding device which is illustrated in detail in Figs. l1, l2 and 13 may then be employed and the roller hangers |45 and |46, and the beltguiding rollers |41 and |48 carried thereby may then be positioned either as shown in full lines or as shown in dotted lines in Fig. l2, or in any other desired position, so as to control the path of travel of the front or outer lap of the abrasive belt 36, where its abrasive surface engages the peripheral edge of the glass disc 35; the position of the hangers |45 and |46 and the guide rollers |41 and |48 depending upon the particular curvature or configuration which it is desired to impart to the peripheral edge of the glass sheet or disc 35.

In the event, however, that it is desired to form a iiat or straight-sided peripheral edge on the glass or like ceramic sheet or disc 35, which is carried by the turntable 31, the belt-guiding device which is illustrated in detail in Figs. 16 and 17 may be employed and the shoe ill- |12 may then be adjusted into and clamped, by means of the set screw |10, in a substantially vertical position, as shown in Fig. 17, so that the iront or outer lap of the abrasive belt 36 will travel in a substantially Vertical plane or path at the point where its abrasive surface engages the peripheral edge of the glass disc 35.

However, in the event that it is desired to form It will be noted, in this connection, that it is desirable to limit the yielding pressure or contact of the peripheral edge portion of the glass sheet or disc 35 against the abrasive surface of the front or outer lap of the abrasive belt 36 until the rough or jagged points or surfaces o-n the peripheral edge of the glass sheet or disc 35 have been polished off by engagement with the abrasive surface of the front lap of the abrasive belt 36 carried thereby, and the shoe |'||-|12, vmay be l0 and this is accomplished by means of the stop adjusted into and clamped in either the position plate |04 which is adjustably mounted on the fclin which these parts are shown in Fig. 19 or in lower 90, as best shown in Figs. 8, 9 and 10. the position in which they are shown in Fig. 20, It will be noted, in this connection, that after or in various other positions, so as to vary and the latch dog 92 has been pivoted, at 9|, out of control the path of travel of the front or outer latching engagement with the latch keeper 0| lap of the abrasive belt 36, at the point where on the follower 90, the weights 85 act, through the abrasive surface thereof engages the perithe exible element or chain 80, to urge the turnpheral edge of the glass disc 35; the adjustment table-supporting carriage 58, toward the abrasive of the parts and the consequent path of travel belt 36, the turntable-supporting carriage travelcf the front or outer lap of the abrasive belt 36 20 ling upon its supporting rollers 15 which ride depending upon the degree or angle of the bevel upon the guideways 16. As the turntable-supwhich it is desired to form in the peripheral edge porting carriage 50 is thus urged toward the of the circular glass sheet or disc 35 which is abrasive belt 36, the hand lever 88 engages the carried by the turntable 31. end portion |040 of the stop plate |04 which is By reference to Figs. 11 and 12 and 16 and 17, 25 adjustably mounted on the follower 90, thereby it will be noted that the abrasive belt-guiding and limiting the extent to which the turntable-supcontrolling device which is shown in Figs. 16 and porting carriage 50 may be moved, by the weights l? (or that which is shown in Figs. 18, 19 and 85, toward the abrasive belt 36, it being under- 20) may be readily substituted for the abrasive stood, in this regard, that the screw 91 which belt-guiding and controlling device which is carries the follower or traveler 90 and the adjustshown in Figs. 11 and 12 by merely replacing able stop plate |04 thereon is carried by the unthe supporting bracket |31, which supports the dercarriage 11 which is adjustable laterally, upon rod upon the supporting frame 42 of the the rollers ||0 and trackways relative to the abrasive belt-supporting and operating structure, abrasive belt 36, but said undercarriage 11 is not and the rod |48 and associated parts, with the 3; adjustable or movable toward or away from the supporting bracket |58 and its supporting arm abrasive belt 36. 153 and associated parte, After the rough or jagged points or surfaces on The selected parts of the abrasive belt-guiding the peripheral edge of the glass disc 35 have been and controlling device having thus been adjusted, eliminated, by engagement with the abrasive suras desired, the abrasive belt 36 may then be set lo face of the abrasive belt 36, in the manner dein motion by closing a suitable starting switch (not shown) associated with the motor-driven operating mechanism 43 for the abrasive belt 36.

The substantially circular sheet 35 of glass or scribed above, the turntable-supporting carriage 50, the turntable 31 carried thereby, and the glass disc 35 on the turntable 31, may then be freed torenable the weights 85 and the exible element 80 to urge the peripheral edge portion of the glass sheet or disc 35 into firmer Contact or engagement with the abrasive surface of the i front or outer lap of the abrasive belt 36. Thi-l like ceramic material may then be placed upon the turntable 31 and the turntable-supporting carriage may then be manipulated into its initial or hand wheel |00, and this movement of the screw 91 acts, through the follower 90 thereon, to dispose the turntable-supporting carriage 50, the turntable 31 carried thereby, and the peripheral edge of the glass sheet or disc 35 mounted thereon in approximate adjustment with or relative to the abrasive surface of the abrasive belt 36.

The latch dog 92 may then be' moved out of latching engagement with the latch keeper |0| on the follower 90, which is carried by the screw 91, by lifting the latch dog 92, by means of its handle 95, the latch dog 92 pivoting at its pivotal connection 9| with the hand lever 88 The peripheral edge portion of the glass disc 35 on the turntable 31 will then be urged into yielding engagement with the abrasive surface of the front lap of the abrasive belt 36 by means of the weights S5 acting through the flexible element or chain 80, which is attached, as at 8|, to the upwardly extending arm 82 of the turntable-supporting carriage.

may be accomplished by moving the hand lever 88 laterally, against the action of the spring |09, (right to left as seen in Fig. 10 or top to bottom as seen in Fig. 8) so that it will clear the end portion |040 of the stop plate |04 whereupon the turntable-supporting carriage 50 will be urged closer to the abrasive belt 36, by the weights and flexible element 80, until the hand lever 88, (which in the meantime has been returned to its inner position by the spring |09), engages the resilient element or bumper |04E which is provided on the adjustable stop plate |04.

It will be noted, in this connection, that the extent to which the turntable-supporting carriage 50, the turntable 31 carried thereby and the glass disc 35 mounted on the turntable 31, may be urged toward the abrasive belt 36, and the pressure with which the peripheral edge of the glass disc 35 engages the abrasive belt 36, may be controlled and varied by adjustment of the stop plate |04 on the follower 90, this being accomplished by manipulating the adjusting screw |01 (Figs. 8 and 9) and then clamping the parts in the desired adjusted position by means of the clamping nut |01A which is provided on the screw |01 and is adapted to engage against a portion 90A of the traveler or follower 90. 

